a. Field of the Invention
This disclosure relates to a rotational coupling device such as a brake. In particular, the instant disclosure relates to a rotational coupling device having means for sealing an interface between an armature and an electromagnet of the rotational coupling device.
b. Background Art
One conventional type of rotational coupling device used in industrial applications comprises a spring-set, electromagnetically released brake. In such a brake, a rotor or friction disc is coupled to a rotating member. Springs bias a non-rotating armature into engagement with the rotor, trapping the rotor against a brake plate, in order to engage the brake. An electromagnet is then used to create an electromagnetic circuit to draw the armature away from the rotor when it is desired to disengage the brake.
The above-described brakes work well for their intended purpose. The brakes have drawbacks, however. Dust and other particulate matter often accumulates in the interface between the armature and the electromagnet. The particulate matter can cause damage to the surfaces of the armature and electromagnet and weaken the electromagnetic circuit thereby reducing the operational life of the brake.
The inventor herein has recognized a need for a rotational coupling device that will minimize and/or eliminate one or more of the above-identified deficiencies.